A review of the evidence regarding current dental health practices finds only a few are effective. Brushing twice a day with fluoride toothpaste, using a rotating powered toothbrush, prevents gingivitis and cavities. Using fluoride varnish or sealants can be powerful tools to prevent cavities in children. But the evidence just doesn’t support a lot of other common practices. Flossing, though it does seem to prevent gingivitis and is cheap and easy to do, does not prevent cavities. Really questionable practices include expensive (and often painful) scaling and polishing, yearly dental X-rays, semiannual teeth cleanings, filling cavities with costly bonded amalgams, and interdental (WaterPik) brushing in addition to tooth brushing.